The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 31, 1995
Filed:
Apr. 16, 1993
Wan-Jae Son, Kyungki-do, KR;
Yu-Seon Kim, Kyungki-do, KR;
Samsung Electron Devices Co., Ltd., Kyungki-do, KR;
Abstract
An electron gun for a color cathode ray tube includes a cathode, control and screen electrodes forming a triode, 1st to 3rd focus electrodes forming a first unipotential prefocus lens, 4th and 5th focus electrodes forming a second unipotential prefocus lens with the 3rd focus electrode, a 6th focus electrode forming a bipotential prefocus lens with the 5th electrode adjacent thereto, and an accelerating electrode for forming a bipotential main focus lens with the 6th focus electrode. Vertically-elongated electron beam passing holes are respectively formed in the outgoing planes of the 1st, 3rd and 5th electrodes and horizontally-elongated electron beam passing holes are respectively formed in the incoming planes of the 3rd, 5th and 6th focus electrodes. The 2nd and 4th focus electrodes are supplied with a predetermined first static focus voltage, the 3rd and 5th focus electrodes are supplied with a second static focus voltage higher than the first static focus voltage, and the 1st and 6th focus electrodes are supplied with a dynamic focus voltage which is synchronized with a deflection signal and whose negative peak equals the second static focus voltage. The astigmatism of an electron beam spot on the periphery of the screen is improved using a dynamic quadrupole lens, thereby forming an almost circular beam spot with a small halo. Also, the focusing distance is adjusted by the dynamic variation of the intensity of a main lens, so that the spot size formed on the periphery approaches that on the center of the screen.